/*
 *  *What is the greatest product of four adjacent numbers in any direction (up, down, left, right, or diagonally) in the 2020 grid?
 *   */

#include<stdio.h>

 int grid[][20] = {
{8,2,22,97,38,15,0,4,0,75,4,5,7,78,52,12,5,77,91,8},
{49,49,99,4,17,81,18,57,6,87,17,4,98,43,69,48,4,56,62,},
{81,49,31,73,55,79,14,29,93,71,4,67,53,88,3,3,49,13,36,65},
{52,7,95,23,4,6,11,42,69,24,68,56,1,32,56,71,37,2,36,91},
{22,31,16,71,51,67,63,89,41,92,36,54,22,4,4,28,66,33,13,8},
{24,47,32,6,99,3,45,2,44,75,33,53,78,36,84,2,35,17,12,5},
{32,98,81,28,64,23,67,1,26,38,4,67,59,54,7,66,18,38,64,7},
{67,26,2,68,2,62,12,2,95,63,94,39,63,8,4,91,66,49,94,21},
{24,55,58,5,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72},
{21,36,23,9,75,0,76,44,2,45,35,14,0,61,33,97,34,31,33,95},
{78,17,53,28,22,75,31,67,15,94,3,8,4,62,16,14,9,53,56,92},
{16,39,5,42,96,35,31,47,55,58,88,24,0,17,54,24,36,29,85,57},
{86,56,0,48,35,71,89,7,5,44,44,37,44,6,21,58,51,54,17,58},
{19,8,81,68,5,94,47,69,28,73,92,13,86,52,17,77,4,89,55,4},
{4,52,8,83,97,35,99,16,7,97,57,32,16,26,26,79,33,27,98,66},
{88,36,68,87,57,62,2,72,3,46,33,67,46,55,12,32,63,93,53,69},
{4,42,16,73,38,25,39,11,24,94,72,18,8,46,29,32,4,62,76,36},
{2,69,36,41,72,3,23,88,34,62,99,69,82,67,59,85,74,4,36,16},
{2,73,35,29,78,31,9,1,74,31,49,71,48,86,81,16,23,57,5,54},
{1,7,54,71,83,51,54,69,16,92,33,48,61,43,52,1,89,19,67,48}
};

int vertical[17][17];
int linear[17][17];
int lineard[17][17];
int horzonial[17][17];


/* 2010-03-25 */
int main(void)
{
        int i, j;
        int max = 0;
        for(i=0; i<17; i++) {
                for(j=0; j<17; j++) {
                        vertical[i][j] =  grid[i][j]*grid[i][j+1]* grid[i][j+2]* grid[i][j+3];
                        printf("v = %d\n",  vertical[i][j]);
                        horzonial[i][j] =  grid[i][j]*grid[i+1][j]* grid[i+2][j]* grid[i+3][j];
                        printf("h = %d\n",  horzonial[i][j]);
                        linear[i][j] =  grid[i][j]*grid[i+1][j+1]* grid[i+2][j+2]* grid[i+3][j+3];
                        printf("d = %d\n",  linear[i][j]);
                        lineard[i][j] =  grid[i+3][j]*grid[i+2][j+1]* grid[i+1][j+2]* grid[i][j+3];
                        if(  vertical[i][j] > max )
                                max =  vertical[i][j];
                        if(  horzonial[i][j]  > max)
                                max =  horzonial[i][j] ;
                        if( linear[i][j] > max ) 
                                max = linear[i][j] ;
                        if( lineard[i][j] > max ) 
                                max = lineard[i][j] ;
                        printf("%d\n", max);
                }
        }
        printf("%d\n", max);
        return 0;
}
